1. Field of the Invention
As detailed below, this air gun discharge method and apparatus is an invention which addresses the problem of how to increase the projectile range and precision in gas pressure air guns that fire ball-shaped projectiles-for example, as a discharge method and apparatus for guns that fire paint-filled balls.
2. Prior Art
Legal restrictions on CO.sup.2 or compressed air discharge pressure levels limit the range and accuracy of air guns. Various designs to improve air gun performance have thus been proposed. For example, Japanese Patent No. 61-173099 (Tsukiji) proposes a discharge apparatus that will be described next with reference to FIG. 4.
A projectile 5 is supplied to chamber 1 via aperture 2 and forwarded to and held in place by O-ring 4 during the firing process. At the same time, pressure gas is introduced to chamber 1, which pushes forward projectile 5 and O-ring 4 such that projectile 5 is discharged into barrel 3. However, the projectile is discharged without rotation and, therefore, under the pressure limitations of pressure gas, no improvements in range or precisions are realized.
Recently, it has been proposed that rotation be given to a projectile to improve air gun performance. Japanese Patent No. 3-35997 (Morioka) discloses a means for placing counter-gravitational spin on a ball-shaped projectile. This known prior art uses an irregularly shaped elastic cylinder to seat a ball projectile, with a peg-like protuberance set above the cylinder and extending downwards; upon discharge, the ball hits the bolt causing the projectile to spin in an upward direction vertical and opposite to the gravitational force. In this known prior art, the upper portion of the flexible cylinder is squeezed between the tip of the bolt and the projectile, making the cylinder susceptible to tearing due to the stress of discharge. Moreover, the obstructive bolt and the air pressure that escapes out the chamber through the irregular elastic cylinder combine to create an unstable trajectory and only minor improvements in projectile performance.